Electronic devices having displays with expanded edges

ABSTRACT

An electronic device may be provided with a display. The display may have a flexible display layer covered by a protective display cover layer. The flexible display layer may be an organic light-emitting diode display layer or other layer with a flexible substrate. The flexible display layer may have a central region with peripheral edges. The central region may be rectangular, may be octagonal, or may have other shapes. Strip-shaped protrusions may extend along each of the peripheral edges of the central region. The strip-shaped protrusions may be bent to provide the protrusions with curved surface profiles. The display cover layer may have a cushion shape with bowed edges that overlap parts of the strip-shaped protrusions, may have curved inner and outer surfaces and/or planar surfaces, may have rounded corners with compound curvature, may have edges with curved surface profiles, and/or may have other configurations.

This application is a continuation of U.S. patent application Ser. No.16/390,850, filed Apr. 22, 2019, which claims the benefit of provisionalpatent application No. 62/683,328, filed Jun. 11, 2018, both of whichare hereby incorporated by reference herein in their entireties.

FIELD

This relates generally to electronic devices, and, more particularly, toelectronic devices with displays.

BACKGROUND

Electronic devices such as cellular telephones, tablet computers, andother electronic equipment may include displays for presenting images toa user.

If care is not taken, electronic devices with displays may not have adesired appearance or may be difficult to use satisfactorily. Forexample, displays may be bulky and unattractive or may not accommodate adesired electronic device shape.

SUMMARY

An electronic device may be provided with a display. The display mayhave a flexible display layer covered by a protective display coverlayer. The flexible display layer may be an organic light-emitting diodedisplay layer or other layer with a flexible substrate. The displaycover layer may be formed from a layer of glass, clear polymer, or otherprotective material.

The flexible display layer may have a central region with peripheraledges. The central region may be rectangular, may be octagonal, or mayhave other shapes. Strip-shaped protrusions may extend along each of theedges of the central region. The strip-shaped protrusions may be bentdownwardly so that the protrusions have curved surface profiles.

The display cover layer, which may be formed from a layer of glass,clear polymer, or other protective material may have a cushion shapewith edges that bow outwardly to partially overlap the strip-shapedprotrusions. The display cover layer may have curved inner and outersurfaces and/or planar surfaces, may have rounded corners with compoundcurvature, may have edges with curved surface profiles, and/or may haveother configurations.

Housing structures may overlap gaps formed at corners of the centralregion. The housing structures may be formed from opaque material suchas metal and may help block the corners from view from the exterior ofthe electronic device.

Inactive tail portions of the flexible display may extend from thestrip-shaped protrusions and may overlap each other on a rear portion ofthe display layer where signal paths in the inactive tail portions arecoupled to display driver circuitry.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an illustrative electronic device in accordancewith an embodiment.

FIG. 2 is schematic diagram of an illustrative electronic device inaccordance with an embodiment.

FIG. 3 is a cross-sectional side view of portion of a display andinternal components in an illustrative electronic device in accordancewith an embodiment.

FIG. 4 is perspective view of an illustrative flexible display layerhaving bent edge protrusions in accordance with an embodiment.

FIG. 5 is perspective view of an illustrative display cover layer inaccordance with an embodiment.

FIGS. 6 and 7 are cross-sectional side views of illustrative displaycover layers in accordance with embodiments.

FIG. 8 is a rear perspective view of an illustrative flexible display inaccordance with an embodiment.

FIG. 9 is a top view of a corner portion of an illustrative flexibledisplay in accordance with an embodiment.

FIG. 10 is a top view of an illustrative flexible display with edgeprotrusions in accordance with an embodiment.

FIG. 11 is a top view of an illustrative display cover layer with acushion shape in accordance with an embodiment.

FIG. 12 is a top view of an illustrative electronic device with adisplay cover layer of the type shown in FIG. 11 in accordance with anembodiment.

FIGS. 13 and 14 are cross-sectional side views of edge portions ofillustrative electronic devices in accordance with embodiments.

FIG. 15 is a top view of an illustrative flexible display with anoctagonal central portion in accordance with an embodiment.

DETAILED DESCRIPTION

Electronic devices may be provided with displays. The displays may havecurved surfaces. For example, a display may have a rectangular shapewith rounded corners and edges with curved profiles. Electronic devicedisplays with curved surfaces may have an attractive appearance, may beviewed from a variety of different angles, and may have a desirablylarge area available for displaying images.

A top view of an illustrative electronic device with a display is shownin FIG. 1. As shown in FIG. 1, device 10 may have a display such asdisplay 14 mounted in housing 12. Housing 12, which may sometimes bereferred to as an enclosure or case, may be formed of plastic, glass,ceramics, fiber composites, metal (e.g., stainless steel, aluminum,titanium, gold, etc.), other suitable materials, or a combination of anytwo or more of these materials. Housing 12 may be formed using a unibodyconfiguration in which some or all of housing 12 is machined or moldedas a single structure or may be formed using multiple structures (e.g.,an internal frame structure, one or more structures that form exteriorhousing surfaces, etc.).

If desired, a strap such as strap 30 or other external structures may becoupled to housing 12 (e.g., using spring bars, magnets, threadedfasteners, clips, or other coupling structures). Strap 30 may be a wriststrap with a clasp such as clasp 32 that is configured to allow device10 to be worn by a user. Strap 30 may be formed from metal, fabric,natural materials such as leather, polymer, or other materials. Clasp 32may be a magnetic clasp, a mechanical clasp, or other suitable clasp.Device 10 may be a wristwatch that is worn on a user's wrist or otherwearable device. If desired, device 10 may be a cellular telephone,tablet computer, desktop computer, display device, or other suitableequipment including a display. The use of display 14 in a wearableportable device such as a wristwatch device is sometimes describedherein as an example.

Display 14 may be a liquid crystal display, an organic light-emittingdiode display having an array of thin-film organic light-emitting diodepixels on a flexible substrate, or a display based on other displaytechnologies (e.g., an electrophoretic display, a display having anarray of crystalline semiconductor light-emitting diodes on a flexiblesubstrate, etc.). Display 14 may be a touch screen display thatincorporates a layer of conductive capacitive touch sensor electrodes orother touch sensor components (e.g., resistive touch sensor components,acoustic touch sensor components, force-based touch sensor components,light-based touch sensor components, etc.) or may be a display that isnot touch-sensitive.

Display 14 may include one or more layers of transparent protectivematerial. For example, the outermost layer of display 14, which maysometimes be referred to as a display cover layer, may be formed from ahard transparent material such as glass, rigid polymer, sapphire orother crystalline material, or other clear material to help protectdisplay 14 from damage.

A schematic diagram of electronic device 10 is shown in FIG. 1. Device10 may include control circuitry 20. Control circuitry 20 may includestorage and processing circuitry for supporting the operation of device10. The storage and processing circuitry may include storage such asnonvolatile memory (e.g., flash memory or otherelectrically-programmable-read-only memory configured to form a solidstate drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Processing circuitry in control circuitry 20may be used to gather input from sensors and other input devices and maybe used to control output devices. The processing circuitry may be basedon one or more microprocessors, microcontrollers, digital signalprocessors, baseband processors and other wireless communicationscircuits, power management units, audio chips, application specificintegrated circuits, etc.

To support communications between device 10 and external equipment,control circuitry 20 may communicate using communications circuitry 22.Circuitry 22 may include antennas, wireless transceiver circuitry suchas radio-frequency transceiver circuitry, and other wirelesscommunications circuitry and/or wired communications circuitry.Circuitry 22, which may sometimes be referred to as control circuitryand/or control and communications circuitry, may support bidirectionalwireless communications between device 10 and external equipment over awireless link (e.g., circuitry 22 may include radio-frequencytransceiver circuitry such as wireless local area network transceivercircuitry configured to support communications over a wireless localarea network link, near-field communications transceiver circuitryconfigured to support communications over a near-field communicationslink, cellular transceiver circuitry such as cellular telephonetransceiver circuitry configured to support voice and/or datacommunications over a cellular telephone link, or transceiver circuitryconfigured to support communications over any other suitable wired orwireless communications link). Wireless communications may, for example,be supported over a Bluetooth® link, a WiFi® link, a 60 GHz link orother millimeter wave link, a cellular telephone link handling voiceand/or data, or other wireless communications link. Device 10 may, ifdesired, include power circuits for transmitting and/or receiving wiredand/or wireless power and may include batteries or other energy storagedevices. For example, device 10 may include a coil and rectifier toreceive wireless power that is provided to circuitry in device 10.

Device 10 may include input-output devices such as devices 24.Input-output devices 24 may be used in gathering user input, ingathering information on the environment surrounding the user, and/or inproviding a user with output. During operation, control circuitry 20 mayuse sensors and other input devices in devices 24 to gather input andcan control output devices in devices 24 to provide desired output.

Devices 24 may include one or more displays such as display 14. Display14 may have an array of pixels configured to display images for a user.The display pixels may be formed on a substrate such as a flexiblesubstrate (e.g., display 14 may be formed from a flexible displaypanel). Conductive electrodes for a capacitive touch sensor in display14 and/or an array of indium tin oxide electrodes or other transparentconductive electrodes overlapping display 14 may be used to form atwo-dimensional capacitive touch sensor for display 14 (e.g., display 14may be a touch sensitive display).

Sensors 16 in input-output devices 24 may include force sensors (e.g.,strain gauges, capacitive force sensors, resistive force sensors, etc.),audio sensors such as microphones, touch and/or proximity sensors suchas capacitive sensors (e.g., a two-dimensional capacitive touch sensorintegrated into display 14, a two-dimensional capacitive touch sensoroverlapping display 14, and/or a touch sensor that forms a button,trackpad, or other input device not associated with a display), andother sensors. If desired, sensors 16 may include optical sensors suchas optical sensors that emit and detect light, ultrasonic sensors,optical touch sensors, optical proximity sensors, and/or other touchsensors and/or proximity sensors, monochromatic and color ambient lightsensors, image sensors, fingerprint sensors, temperature sensors,sensors for measuring three-dimensional non-contact gestures (“airgestures”), pressure sensors, sensors for detecting position,orientation, and/or motion (e.g., accelerometers, magnetic sensors suchas compass sensors, gyroscopes, and/or inertial measurement units thatcontain some or all of these sensors), health sensors, radio-frequencysensors, depth sensors (e.g., structured light sensors and/or depthsensors based on stereo imaging devices), optical sensors such asself-mixing sensors and light detection and ranging (lidar) sensors thatgather time-of-flight measurements, humidity sensors, moisture sensors,gaze tracking sensors, and/or other sensors. In some arrangements,device 10 may use sensors 16 and/or other input-output devices to gatheruser input (e.g., buttons may be used to gather button press input,touch sensors overlapping displays can be used for gathering user touchscreen input, touch pads may be used in gathering touch input,microphones may be used for gathering audio input, accelerometers may beused in monitoring when a finger contacts an input surface and maytherefore be used to gather finger press input, etc.).

If desired, electronic device 10 may include additional components (see,e.g., other devices 18 in input-output devices 24). The additionalcomponents may include haptic output devices, audio output devices suchas speakers, light producing output devices such as light-emittingdiodes for status indicators, light sources such as light-emittingdiodes (e.g., crystalline semiconductor light-emitting diodes) thatilluminate portions of a housing, gaps in displays, and/or other displaystructures, other optical output devices, and/or other circuitry forgathering input and/or providing output. Device 10 may also include abattery or other energy storage device, connector ports for supportingwired communication with ancillary equipment and for receiving wiredpower, and other circuitry.

A cross-sectional side view of an edge portion of an illustrativedisplay and associated internal components in device 10 is shown in FIG.3. As shown in FIG. 3, the interior of device 10 may include one or moreprinted circuit such as printed circuit 48 with electrical components50. Components 50 may include integrated circuits (e.g., controlcircuitry 20, communications circuitry 22), input-output devices 24 suchas sensors 16 and devices 18, and other circuitry.

As shown in the illustrative configuration of FIG. 3, display 14 may bemounted on front face FR of device 10 and housing 12 may be formed onopposing rear face RR of device 10. Housing 12 and/or portions ofdisplay 14 may form sidewall portions of device 10 such as sidewall E.

Display 14 may include a flexible display layer such as flexible displaylayer 42 having an array of pixels 44 on a flexible substrate (e.g., apolyimide substrate or other flexible polymer layer). Pixels 44 may becrystalline semiconductor light-emitting diode pixels or pixels formedthin-film organic light-emitting diodes and other thin-film circuitry.Display layer 42 may be covered with a transparent protective layer suchas display cover layer 40. Display cover layer 40 may be formed fromglass, polymer, crystalline material such as sapphire, or othertransparent material and/or combinations of these materials. A layer ofadhesive (polymer) such as layer 46 may be used to attach display layer42 to the inner surface of display cover layer 40, if desired. In someconfigurations, an internal frame structure may be provided to supportsome or all of display layer 42 (e.g., from the underside of layer 42).

In the example of FIG. 3, display cover layer 40 has inner and outersurfaces with curved profiles. If desired, the surfaces of display coverlayer 40 may include planar portions (e.g., flat areas associated withthe center of front face FR, vertical sidewall portions on sidewall E,etc.). The configuration of FIG. 3 is illustrative.

Display layer 42 may have any suitable shape. With one illustrativeconfiguration, display layer 42 has a central portion with peripheraledge protrusions that are bent. This type of arrangement is shown inFIG. 4. As shown in FIG. 4, display layer 42 may have a central portionsuch as central portion 42C. Central portion 42C may be planar or mayhave a curved surface profile. The outline (footprint when viewed fromabove) of central portion 42C may be rectangular or portion 42C may havean outline of other suitable shapes. In the example of FIG. 4, centralportion 42C is square and has four peripheral edges. Elongatedstrip-shaped protrusions 42P may protrude from one or more of the fourperipheral edges of portion 42C. For example, there may be protrusions42P on the opposing left and right sides of portion 42C, there may beprotrusions 42P on the opposing upper and lower edges of portion 42C, orthere may be protrusions 42P or all four edges of portion 42C as shownin FIG. 4. Configurations in which there are other numbers ofprotrusions 42P (e.g., three protrusions, at least five protrusions, atleast eight protrusions, etc.) may also be used.

As shown in FIG. 4, the peripheral edge portions of layer 42 may be bentso that the surface of each protrusion 42P has a curved profile. Thisenlarges the outline (footprint) of display layer 42 in the X-Y planewhen viewed from above by viewer 43 in downward direction 45 (the −Zdirection of FIG. 4) while at the same time covering internal componentsin device 10 with portions of display layer 42 when viewed from theside. Gaps G between sets of pixels on respective opposing edges oflayer 42 may be present at the corners of display layer 42, but may, ifdesired, be reduced in size by additional bending of protrusions 42P.Colored ink (e.g., black polymer, polymer colored with a non-neutralcolorant, etc.), light-emitting diodes, or other structures may be usedin gaps G to help obscure gaps G from view. Bezel structures (e.g.,housing structures such as portions of polymer or metal housingsidewalls) and other structures may also be used to visually block gapsG when the display of device 10 is viewed in direction 45.

Display 14 (and associated layers 40 and 42) may be rectangular (e.g.,display 14 may have a rectangular shape with rounded corners), may besquare (e.g., display 14 may have a square outline with roundedcorners), may have a circular or oval outline, or may have othersuitable shapes. A perspective view of display cover layer 40 in anillustrative configuration in which display cover layer 40 is square isshown in FIG. 5. As shown in FIG. 5, display cover layer 40 may have asquare outline with rounded corners when viewed from above in direction45. Display cover layer 40 may have a peripheral edge with four edgesegments (e.g., top, bottom, left, and right peripheral edges), such asperipheral edges 40E. Edges 40E, which may sometimes be referred to assidewall structures, sidewall segments, or side portions of displaycover layer 40 may each have a curved cross-sectional profile (e.g., thesurfaces of edges 40E may be curved).

If desired, device 10 (e.g., display cover layer 40) may have externalsurfaces with compound curvature. In the example of FIG. 5, device 10has edge portions 40E with surfaces that each curve about respectiveedges axes such as axis 53. These portions (and the correspondingprotrusions 42P of display layer 42 that are overlapped by edge portions40E) extend along the straight sides of device 10 and are characterizedby curved surfaces that can be flattened into a plane without distortion(sometimes referred to as developable surfaces). At the corner of device10, display cover layer 40 has curved surface portions 40CC withcompound curvature (e.g., a surface that can only be flattened into aplane with distortion, sometimes referred to as a surface with Gaussiancurvature). Each of the four corners of device 10 may have thisarrangement, if desired.

The central portion of the outer surface of display cover layer 40 maybe planar, as shown by illustrative planar exterior surface 40T ofdisplay cover layer 40 in the cross-sectional side view of FIG. 6.Opposing inner surface 40B of display cover layer 40 may also have aplanar profile in the center of display cover layer, as shown in FIG. 6.The thickness T of layer 40 may, if desired, be uniform across thesurface of layer 40. Edge portions of layer 40 may have curved profilesas described in connection with FIG. 5.

FIG. 7 is a cross-sectional side view of display cover layer 40 in anillustrative configuration in which the center of exterior surface 40Tof display cover layer 40 has a curved profile. The center of opposinginterior surface 40B of layer 40 may be curved (e.g., surface 40B mayhave a curved surface profile matching that of opposing outer surface40T) or may have other shapes (see, e.g., the planar surface profile ofillustrative inner surface 40B′ in the center of layer 40).

FIG. 8 is a rear perspective view of display layer 42 in an illustrativeconfiguration in which layer 42 has bent protruding inactive tailportions. Central portion 42C of display layer 42 may have a squareshape or other rectangular shape (as an example). Edge protrusions 42Pmay extend along the four peripheral edges of the display and may havecurved surface profiles, as described in connection with FIG. 4. Centralportion 42C of display layer 42 and protrusions 42P of display layer 42may have pixels configured to display images. Inactive tail portionssuch as portions 42TL-1 and 42TL-2 may extend from one or more of theedges of display layer 42. These tail portions are free of pixels, butcontain signal paths such as gate lines GL and data lines DL that arecoupled to display driver circuitry such as display driver circuitry 52(e.g., one or more display driver integrated circuits, etc.). Duringoperation, gate lines GL may be used to convey gate line signals (alsosometimes referred to as gate signals, control signals, scan signals,emission control signals, etc.) onto control gates of transistors (e.g.,thin-film transistors) in the pixels of display layer 42 while datelines DL convey corresponding data (pixel values) to the pixels ofdisplay layer 42.

In the illustrative configuration of FIG. 8, tail portion 42TL-1 extendsfrom a first of protrusions 42P and tail portion 42TL-2 extends from asecond of protrusions 42P. These tail portions may be folded underregion 42C and coupled to printed circuit 54 at the rear of displaylayer 42. Printed circuits such as printed circuit 54 may be coupled totail portions 42TL-1 and/or 42TL-2 using conductive adhesive, solder, orother conductive material. Display driver circuitry 52, connectors (forcoupling to display driver circuitry on additional printed circuits),and/or other circuitry in device 10 may be mounted on printed circuit 54and/or otherwise coupled to printed circuit 54 and/or display layer 42.Printed circuit 54 may be a rigid printed circuit (e.g., a printedcircuit board formed from fiberglass-filled epoxy or other rigid printedcircuit board material) or may be a flexible printed circuit. Ifdesired, display driver circuitry 52 may be mounted directly on aportion of display layer 42 (e.g., using conductive adhesive, solder,etc.)

The outermost border areas of layer 42 may form inactive areas ofdisplay 14. As shown in the illustrative corner portion of display layer42 of FIG. 9, layer 42 may, for example, have a border such as inactivearea IA that is free of pixels, but that contains metal traces formingsignal paths 64 for carrying power signals, control signals, and/or datasignals for display 14. Bend axes 60 and 62, about which respectiveprotrusions 42P are bent, may be located away from corner 65 of thesubstrate of layer 42 and the pixels of layer 42 so that bending occursin portions of paths 64 that are able to tolerate bending stress. Asshown in FIG. 9, for example, bend axis 60 may be located to the rightof corner 65, so that the strip-shaped protrusion running along theright edge of layer 42 of FIG. 9 experiences bending only at a locationthat is farther to the right than corner 65 and bend axis 62 may belocated below corner 65, so that the strip-shaped protrusion runningalong the lower edge of layer 42 of FIG. 9 experiences bending only at alocation that is farther down than corner 65. In this way, bending ofthe strip-shaped protrusions is limited to areas of layer 42 wherecompound curvature (spherical bent surfaces) will not be created. Ifdesired, bend axis 60 may be located inboard of corner 65 (slightly tothe left of corner 65 of FIG. 9) and bend axis 62 may be located inboardof corner 65 (slightly above corner 65). Configurations such as these inwhich the bend axes of the strip-shaped protrusions are located inboardof the corners of layer 42 may give rise to small amounts of compoundcurvature (spherical bending), but this can be acceptable in appropriatesituations provided that the circuitry located in the area of compoundcurvature is not overly sensitive to stress.

FIG. 10 is a top view of display layer 42 in an illustrativeconfiguration in which central display layer region 42C is rectangular(e.g., square) and in which strip-shaped protrusions 42P extend alongeach of the four peripheral edges of central region 42C. Portions 42Cand 42P contain pixels configured to display an image such as an imagecontaining illustrative image content 66 (e.g., a circular clock face,clock hands, numerals, other content for a clock face, and/or othercontent).

Inactive tail portions of layer such as tail portion 42TL do not containpixels and therefore do not display any part of image content 66. Eventhough corner portions of display layer 42 are missing, it is possibleto display content such as illustrative image content 66 that extendsonto one or more of protrusions 42P in addition to portion 42C. In somesituations, such as when a visual element in a displayed image such asimage content 66 is circular as shown in FIG. 10 or when the content inprotrusions 42P includes dark background content that tends to visuallyblend with the missing corners of layer 42 (e.g., content that tends tovisually blend with gaps G in FIG. 4), little or no content of interestneeds to be omitted due to the absence of pixels in the corners of layer42. For example, icons, text, clock face content, and/or other contentcan be centralized while portions of this content extend into the pixelsof protrusions 42P.

The content being displayed on layer 42 can therefore be configured tominimize the impact of missing corner portions of display layer 42. Forexample, control circuitry 20 can be configured to display text oncentral portions of protrusions 42P without extending text or otherpotentially important information onto the areas of display 14associated with the missing corners of layer 42. In some arrangements,icons, time information, date information, and/or other ancillaryinformation may be displayed on protrusions 42P. Configurations in whichbackground content (e.g., a solid color or pattern) is displayed inprotrusions 42P may also be used.

If desired, display cover layer 40 may have a shape that minimizesoverlap with the missing corners of display layer 42. Consider, as anexample, illustrative display cover layer 40 of FIG. 11. In thisexample, display cover layer 40 has a cushion shape (sometimes referredto as a pillow shape or barrel shape). If desired, the corners 70 ofdisplay cover layer 40 may be aligned with the corresponding corners oflayer (see, e.g., corners 65 of layer 42 of FIG. 9). As shown in FIG.11, the central portions of opposing upper and lower peripheral edges 72of cushion-shaped layer 40 bow outwardly from central portion 42C andpartially overlap respective upper and lower protrusions 42P. Thecentral portions of opposing left and right peripheral edges 72 of layer40 likewise bow outwardly from central portion 42C and partially overlaprespective protrusions 42P on the left and right sides of display layer42. In this way, some or all of the central portion of each protrusion42P may be covered with a corresponding bowed out edge portion ofdisplay cover layer 40 (e.g., while little or none of the missingcorners of display layer 42 are covered with layer 40). This helps hidegaps G while enhancing the area of display layer 42 that is availablefor displaying image content.

As shown in FIG. 12, a portion of the housing of device 10 (e.g., bezel80 of FIG. 12 or other housing structures, which may be formed frommetal or other material) may be formed around the peripheral edge ofdisplay cover layer 40, thereby helping to hide the missing corners(gaps G) of display layer 42 from view.

If desired, display layer 42 may be bent sufficiently that inactive tailportions of layer 42 are hidden from view from the front of device 10.Consider, for example, illustrative device 10 of FIG. 13. In the exampleof FIG. 13, display layer 42 has an active area with pixels 44 fromwhich inactive tail portion 42TL extends downwardly into the interior ofdevice 10. Display cover layer 40 may have a curved edge portion that iscoupled to housing walls 82 using adhesive 84 or other mountingstructures. Housing walls 82 may, if desired, be formed from opaquematerial such as metal or transparent material that is covered withopaque ink or other opaque coating layers. When device 10 is beingviewed from the side, inactive tail portion 42TL may be hidden from viewfrom the exterior of device 10 by housing walls 82. When device 10 isbeing viewed from above in direction 45, tail portion 42TL may bepartially or completely blocked from view by housing walls 82 and thevertical or nearly vertical arrangement of the exterior surface of layer40 along edge portion 40E.

Another illustrative configuration for device 10 is shown in FIG. 14. Asshown in the example of FIG. 14, the housing of device 10 may haveportions on the rear and side of device 10. For example, a housing wallsuch as rear housing wall 82-2 may extend over some or all of the rearface of device 10 and a metal sidewall structure in the housing ofdevice 10 such as sidewall 82-1 may extend over some or all of the edgeof device 10. Housing structures such as walls 82-1 and 82-2 may beformed from opaque material such as metal, opaque polymer, etc. or maybe formed from transparent materials covered with opaque coatings (asexamples).

Adhesive or other material 84 may be used in coupling display coverlayer 40 to housing portion 82-1 and in coupling housing wall portions82-1 and 82-2 together. Display layer 42 may be configured so that theactive portion of layer 42 is visible in direction 45 by viewer 43 whileinactive tail portion 42TL extends behind opaque structures in device 10such as sidewall 82-1. Due to the curvature of display cover layer 40and wall 82-1 near the edge of device 10, the active area of display 14(e.g., the pixels of display layer 42) may be viewed in direction 45through display cover layer 40 while inactive tail 42TL is blocked fromview. If desired, the outermost peripheral portion of housing sidewall82-1 may be configured to be nearly vertical to help maximize the areaof device 10 in which images are displayed (e.g., area 88) relative tothe width of the inactive border areas of device 10 in which no imagesare displayed (e.g., area 86).

If desired, device 10, display cover layer 40, and display layer 42 mayhave non-rectangular outlines. For example, device 10, display coverlayer 40, and display layer 42 may have an octagonal outline or otheroutline with fewer than four edges or more than four edges (and/or withany number of edges that include straight and/or curved segments). Inthe top view of display layer 42 of FIG. 15, display layer 42 has anillustrative octagonal layout with eight strip-shaped protrusions 42P,each of which extends along a corresponding one of eight straightsegments of the periphery of octagonal central portion 42C of displaylayer 42. Protrusions 42P may be bent out of the plane of centralportion 42C of layer 42 and may have curved surface profiles. Inactivetail portions 42TL may extend outwardly from one or more of protrusions42P and may contain signal paths coupled to display driver circuitry, asdescribed in connection with FIG. 8. Although the example of FIG. 15involves the use of eight edge, display layer 42 may have any suitablenumber of edges. For example, display layer 42 may have more than eightedges (e.g., at least nine edges, at least ten edges, at least 12 edges,at least 16 edges, fewer than 32 edges, etc.). Arrangements with moreedges may help form a display footprint that is closer to an idealcircular shape, but may potentially reduce the amount of active area onthe bent protrusions that is available for displaying images.

The foregoing is merely illustrative and various modifications can bemade to the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. An electronic device, comprising: a flexibledisplay having a central portion and bent edges each extending from thecentral portion; and a display cover layer that overlaps the flexibledisplay, wherein the display cover layer has corners with compoundcurvature and has curved edges that each extend between two of thecorners and overlap a respective one of the bent edges.
 2. Theelectronic device defined in claim 1 wherein the bent edges comprisefirst, second, third, and fourth bent edges.
 3. The electronic devicedefined in claim 2 wherein the curved edges comprise first, second,third, and fourth curved edges.
 4. The electronic device defined inclaim 1 wherein the display cover layer comprises a glass display coverlayer and wherein the flexible display comprises a flexible organiclight-emitting diode display layer, the electronic device furthercomprising: a metal housing coupled to the display cover layer; a wriststrap coupled to the metal housing; and wireless transceiver circuitryconfigured to transmit and receive wireless signals.
 5. The electronicdevice defined in claim 1 wherein the curved edges of the display coverlayer comprise opposing inner and outer surfaces with curved profiles.6. The electronic device defined in claim 1 wherein the display coverlayer comprises a planar portion that overlaps the central portion ofthe flexible display.
 7. The electronic device defined in claim 1wherein the flexible display comprises gaps between the bent edges. 8.The electronic device defined in claim 7 wherein the gaps are hiddenfrom view by a housing structure.
 9. The electronic device defined inclaim 7 wherein the gaps are hidden from view by a colored ink.
 10. Theelectronic device defined in claim 1 wherein the flexible displaycomprises a pixel array that extends onto at least some of the bentedges.
 11. An electronic device, comprising: a housing; a display coverlayer coupled to the housing, wherein the display cover layer has firstand second curved edges, a corner between the first and second curvededges, and compound curvature at the corner; and a flexible displaylayer that is overlapped by the display cover layer, wherein theflexible display layer has a rectangular central portion and first andsecond strip-shaped protrusions that extend from the rectangular centralportion, wherein the first and second strip-shaped protrusions includepixels and are respectively overlapped by the first and second curvededges.
 12. The electronic device defined in claim 11 wherein the firstand second strip-shaped protrusions are separated by a gap.
 13. Theelectronic device defined in claim 12 wherein the corner covers the gap.14. The electronic device defined in claim 12 wherein the flexibledisplay layer comprises signal lines that are routed around the gap. 15.The electronic device defined in claim 11 wherein the display coverlayer has a curved inner surface and wherein the pixels are mountedagainst the curved inner surface of the display cover layer.
 16. Anelectronic device, comprising: a housing; a display cover layer coupledto the housing, wherein the display cover layer comprises four curvededges and four corners with compound curvature; and a flexible displaylayer that is overlapped by the display cover layer, wherein theflexible display layer comprises a central portion and four bent edgesextending from the central portion, wherein the four bent edges areseparated from one another by gaps that are overlapped by the fourcorners of the display cover layer.
 17. The electronic device defined inclaim 16 wherein the flexible display layer comprises a pixel array thatdisplays images across the central portion and the four bent edges. 18.The electronic device defined in claim 16 wherein the display coverlayer comprises glass.
 19. The electronic device defined in claim 16wherein the four curved edges of the display cover layer have curvedinner and outer surfaces.
 20. The electronic device defined in claim 16further comprising a wrist strap, wherein: the housing comprises a metalhousing; the wrist strap is coupled to the metal housing; the displaycover layer comprises a square glass layer; and the flexible displaylayer comprises an organic light-emitting diode display layer.